MOVEMENTS OF THE STOMACH. 135 



pider to be due either, as Ludwig 1 and Schiff" 2 suppose, to the reflex action 

 of the ganglia of the Sympathetic, which are very numerous in the connec- 

 tive-tissue layers of its parietes, or possibly to the contractions of the mus- 

 cular fibres produced by direct irritation, a view which, originally advanced 

 by the author, has been lately strongly advocated by Engelrnann. 3 The 

 moderate excitement of pleasurable emotions is favorable to the operation 

 of digestion ; not only by giving firmness and regularity to the action of the 

 heart, and thus promoting the circulation of the blood and the increase of 

 the gastric secretion ; but also in all probability by imparting energy and 

 regularity to the muscular contractions of the stomach. The movements of 

 the stomach cease during sleep (Busch). 



93. Much discussion has taken place upon the question, how far contrac- 

 tion of the parietes of the Stomach itself actually participates in the opera- 

 tion of Vomiting ; and many experiments have been made to determine the 

 facts of the case. Some, like Magendie, have gone so far as to affirm that 

 the stomach is essentially passive; grounding this inference upon the fact 

 experimentally ascertained, that when the stomach was removed, and a blad- 

 der was substituted for it, this was emptied of its contents by the compression 

 of the parietes of the abdomen, when tartar emetic was injected into the 

 veins. 4 But this fact by no means disproves the active co-operation of the 

 stomach ; and judging from the analogy of the uterus, bladder, and rectum 

 whose muscular walls are all actively concerned in the expulsion of their 

 contents, though that expulsion is in great part clue to the contraction of 

 the abdominal muscles we should be led to concur with the common 

 opinion, of which our own sensations during the act would indicate the cor- 

 rectness. From the careful experiments of Schiff 5 on dogs, as well as from 

 observations made on man in cases where, from injury, the stomach has been 

 exposed, 6 it appears that under ordinary circumstances the cardiac aperture 

 is firmly closed ; but that when vomiting is about to take place, a full inspi- 

 ration occurs, which serves, as Dr. M. Hall first pointed out, to fix the dia- 

 phragm and to supply a firm surface against which the stomach can be 

 pressed. Then, an instant before the contraction of the abdominal walls 

 occurs, the cardiac orifice is suddenly dilated by the contraction of special 

 bauds of muscular fibres, which are probably continuous with the longi- 

 tudinal fibres of the oesophagus. The muscles of expiration i. e., the ab- 

 dominal muscles then contract with great vigor, and the glottis being 

 closed, so that the escape of air from the chest and the elevation of the dia- 

 phragm are prevented, the stomach is subjected to considerable pressure, 

 and its contents are immediately ejected. The importance of the contrac- 

 tion of the abdominal muscles is sufficiently evidenced by the fact, demon- 

 strated by Giannuzzi, that no vomiting can be induced in animals, whose 

 voluntary muscles have been paralyzed by woorara. When peristaltic 

 movements of the stomach, which have occasionally been observed to be 

 reversed in direction, are already present, their activity is generally intensi- 

 fied ; but if the stomach be quiescent before vomiting commences, it may 

 remain perfectly passive throughout. The pylorus is almost always firmly 

 closed, so that but little of the food escapes into the intestines. The flow of 



1 Physiologic, p. 614. 2 Untersuchungen zur Naturlehre, viii, p. 3:23. 



Pfluger's^Archiv, Band iv, 1871, p. 1. 



4 Sehift' lias pointed out that for Magendie's experiment to succeed, the cardiac 

 orifice and lower part of the oesophagus must also be removed, the contraction of 

 these parts otherwise preventing the escape of the contents of the bladder. 



5 Moleschott's Unters., Bd. x, 18G7, p. 353. 



6 Lepine, Bullet, de 1'Acad. Rov. do Med., 1844 ; and Patry, in Allgem. Med. Cen- 

 tralblatt, 1863, No. 62. 



